Hydropneumatic accumulator



W. MESSINGER HYDRO-PNEUMATIC ACCUMULATOR Filed Aug. 10, 1945 5Sheets-Sheet 4 20 Z? i r"\ d 1 Z \J i 9 T1 INVENTOR. Ilka/w Mass/mas?afrmmm-y Aug. 26, 1947.

w. MESSINGER HYDRO-PNEUMATIC ACGUMULATOR I Filed Aug. 10, 1945 5Sheets-Sheet 5:

MM K 5 76 INVENTOR. I

fill/14M MESS/N65? BY V v ATTORNEY i atentecl Aug. 26, 1947 UNITEDSTATES PATENT OFFICE HYDROPNEUMATIC ACCUMULATOR William Messinger,Philadelphia, Pa. Application August 10, 1945, Serial No. 610,095

7 Claims. 1

This invention relates to a pressure intensifier or accumulator formaintaining a supply of liquid, most commonly water or oil, continuouslyunder pressure. Heretofore this was accomplished by the use of a pumpdriven by an electric motor, which forced liquid into a chargingcylinder against weight or other resisting force.

It is one object of this invention to accompish the function describedabove Without employing a motor and pump. For this purpose I propose toutilize the mill supply of compressed air, which is usually maintainedat 80 to 100 lbs/sq. in. In this manner the initial expense and overallspace occupied by the equipment, as well as maintenance costs, aresubstantially reduced.

A further object of this invention consists in utilizing the mill supplycompressed air to force liquid from a reservoir into a charging cylinderfrom which the liquid is withdrawn for use, and

after the cylinder has been charged to a predetermined degree, cuttingoff the compressed air from the reservoir and introducing it into a lowpressure or compressed air cylinder for applying pressure to the liquidin the charging cylinder.

It is another object of this invention to provide a pressure accumulatorwhich utilizes millsupply compressed air instead of a motor and pump andwhich operates automatically to apply and to disconnect the air pressurewhen the charging cylinder has been filled and emptied to apredetermined degree.

It is another object of this invention to intensify the mill supply airpressure to make available to the mill hydraulic pressure of a muchhigher magnitude than the mill supply.

Further objects and advantages of this inven tion will become apparentin the following detailed description thereof.

In the accompanying drawings,

Fig. 1 is a vertical section. of a hydro-pneumatic accumulator embodyingmy, invention, the section being taken substantially on the line. i--lof Fig. 4.

Fig. 2 is a vertical section taken substantially on the line 2-2 of Fig.4.

Fig. 3 is a portion of a section taken on the line 3-3 of Fig. 4.

Fig. 4 is a plan View, partly sectioned horizontally on the line 4-4 ofFig. 1.

Fig. 5 is an enlargement of the valve section and bore of Fig. 2. i

Fig. 6 is a view similar to Fig. 5 showing the valve in anotheroperating position.

Referring to the drawings, the hydro-pneu matic accumulator embodyingthis invention may comprise a casing it) within which is formed a liquidreservoir II, a charging cylinder [2, a compressed air cylinder 13 and avalve mechanism Hi. Liquid from the reservoir Ii is forced into thecharging cylinder 12, in a manner to be described, and the liquid isthen held under pressure by means of a piston I5 operating in thecharging cylinder and forming part of a compound piston element Ithaving another piston i! operating in the compressed air cylinder [3.

Compressed air is supplied to the compressed air cylinder, in a mannerto be described, beneath piston ll so as to maintain pressure on theliquid in the charging cylinder, and a multiplication of the pressuremay be obtained by forming the area of the piston ll larger than thearea of piston I5. By this means, for example, mill supply pressure of100 lbs/sq. in. may be utilized to supply hydraulic pressure of 1600lbs/sq. in. The control of the flow of liquid from the reservoir to thecharging cylinder and the control of the compressed air is efiected bythe valve mechanism which may comprise a hollow tubular valve member 20operating within a bore 2| within the accumulator casing It).

In the position of the parts shown in Figs. 1 and 2, the chargingcylinder I? has been filled with liquid and compressed air has been fedinto the bottom of compressed air cylinder [3 for maintaining the pistonelement, and hence the liquid in the charging cylinder, under pressure.In this position of the elements, compressed air from the mill-supplywhich is under to lbs. pressure is supplied through pipe connection 25and hole 26 connecting with the bore 2|. In the position of the valveshown in Figs. 1, 2 and 5, the hole 26 connects with an annular chamber2'! formed within the valve body 20, and the annular chamber 27communicates with an annular groove 36 in the casing and with horizontalhole 3|, vertical hole 32 and horizontal hole 33 leading directly intothe bot tom of compressed air cylinder iii. In this position of theparts, therefore, mill-supply compressed air from pipe connection 2'5 isbeing supplied to the compressed air cylinder below piston IT to applythis pressure to the liquid in the charging cylinder 12.

As the liquid under pressure is withdrawn from the charging cylinderthrough the check Valve 35 for use in the various mill operations, thepiston element will travel upwardly until a predetermined amount ofliquid has been withdrawn from the charging cylinder, or, stateddifferently, until the charging cylinder has emptied to a predetermineddegree at which point it is necessary to operate the valve mechanism soas to accomplish the function of replenishing the liquid in the chargingcylinder.

To accomplish the above function, the piston element IS has fixedthereto a tappet rod 31 which carries a rod collar 38 so positioned thatwhen the charging cylinder has emptied to a predetermined degree and.the piston element 16 has travelled upwardly to a predetermined degreethe tappet rod 3'! sliding upwardly through an opening 39 will cause therod collar 38 to engage an arm 40 fixed to the valve member 20 and willtherefore lift the valve member. Such lifting will, as shown in Fig. 6,accomplish the, following three functions:

(1) Disconnection of the compressed air line from the compressed aircylinder.

(2) Venting of the compressed air from the compressed air cylinder tothe atmosphere.

(3) Application of compressed air to the reservoir to force liquid fromthe reservoir into the charging cylinder.

To accomplish the above functions reference may be made to Fig. 6wherein it is disclosed that lifting of the valve member 29 causes anannular groove 42 in the valve member to register with the annulargroove 38 which through holes 3|, 32 and 33 communicates with thecompressed air cylinder. The annular groove 52 is connected by aplurality of drilled holes 53 to the hollow interior 45 of the valvemember 20 which is open at its upper end to the atmosphere. Therefore,as soon as annular grooves 39 and 42 register, the compressed air in thecylinder l3 will be vented through holes 33, 32, 3!, annular grooves 35and 42, drilled holes 13 and hollow interior 45 of the valve member 26]to the atmosphere. The liquid in the charging cylinder is therefore nolonger under higher than atmospheric pressure.

At the same time that the compressed air cylinder I3 has been conneotedto the atmosphere, its connection to the source of compressed airthrough pipe connection 25 is cut off because the annular chamber 27 hasmoved out of registry with the annular groove 30.

The upward movement of the valve member 29 accomplishes the thirdfunction set forth above, namely, forcing liquid from the reservoir intothe charging cylinder l2, by reason of the fact that the annular chamber2'! which is connected to the pipe connection 25 now registers with anannular groove 59 in the casing which connects by horizontal hole andvertical hole 52 with the reservoir H. The compressed air pressure nowbeing applied to the reservoir 1 l forces liquid from this reservoirthrough strainer 53 into inlet 54 and thence upwardly into pipe 55,vertical drilled hole 56, continuing pipe 51, check valve 58 andhorizontal pipe 59 into the charging cylinder. The cylinder is thuscharged with liquid from the reservoir under pressure from thecompressed air entering through pipe connection 25.

The filling of the charging cylinder continues, and as it does so, thepiston element is depressed since there is only atmospheric pressure inthe compressed air cylinder I3 on the lower side of the piston element.When the charging cylinder has filled to a predetermined degree it isnecessary to perform the following steps:

(1) Disconnect the compressed air line from the reservoir. r

position shown in Fig. 5.

(2) Connect the compressed air line to the compressed air cylinder.

(3) Vent mill-supply pressure from reservoir.

These steps are accomplished by means of another rod collar 70 carriedby the tappet rod 31 and adapted to engage arm 40 of valve member 20 ata predetermined point in the downward travel of the piston element andhence when the charging cylinder has been filled to a predetermineddegree. This engagement of rod collar 10 with the arm 46 lowers thevalve member to the In this position the annular chamber 21 is moved outof registry with annular groove 50 and since annular chamber 21 is incommunication with the source of compressed air, the compressed airpressure is cut off from the annular groove 52] and hence is cut off thereservoir which connects to the annular groove 58 through holes 5| and52. At the same time annular chamber 21 again is brought into registrywith annular groove 38 which is in communication with the compressed aircylinder through holes 3|, 32, and 33, whereby the compressed air isagain supplied to the compressed air piston H. The liquid in thecharging cylinder is therefore again under intensified mill-supplypressure and is maintained so throughout the upward travel of the pistonelement. At the same time an annular chamber 12 is brought into registrywith the annular groove 58, and since chamber 12 communicates with thehollow interior of the valve member 20 through drilled holes 13,mill-supply pressure on the reservoir will be vented to the atmosphere.

This accumulator is often used on a high pressure oil line which forms aclosed system. Discharge out of the high pressure system can be returnedthrough return line connection and check valve 8i. The return oil is atmuch higher pressure than any pressure which can occur in the reservoirH, even in the interval when millsupply air pressure is admitted.Consequently the check valve will always operate to permit the return ofoil to the reservoir I I.

In accordance with the patent statutes, the preferred embodiment of theinvention has been described, but it will be understood that changes maybe made ithin the scope of the appended claims which define theinvention.

Having described my invention, what I claim and desire to secure byLetters Patent is:

1. In combination, an accumulator for maintaining a quantity of liquidcontinuously under pressure, the accumulator having a charging cylinderfor the liquid, said cylinder having an inlet and an outlet, a valvemechanism for controlling said inlet and outlet, a liquid reservoirconnected to the charging cylinder, a source of compressed air, meanswhereby compressed air from the source is applied to the liquid in thereservoir to force the liquid into the charging cylinder, and meansactuated in response to a predetermined amount of liquid supplied to thecharging cylinder for disconnecting the compressed air from thereservoir and applying the pressure of the compressed air to the liquidin the charging cylinder, characterized by a compressed air cylinder, apiston element operating in the charging cylinder and the compressed aircylinder, the liquid acting on one end of the piston element and thecompressed air acting on the other end.

2. In combination, an accumulator for maintaining a quantity of liquidcontinuously under pressure, the accumulator having a charging cylinderfor the liquid, said cylinder having an inlet and an outlet, a valvemechanism for controlling said inlet and outlet, a liquid reservoirconnected to the charging cylinder, a source of compressed air, meanswhereby compressed air from the source is applied to the liquid in thereservoir to force the liquid into the charging cylinder, and meansactuated in response to a predetermined amount of liquid supplied to thecharging cylinder for disconnecting the compressed air from thereservoir and applying the pressure of the compressed air to the liquidin the charging cylinder, characterized by a compressed air cylinder, acompound piston element having one piston operating in the chargingcylinder and another piston operating in the compressed air cylinder,the liquid acting on one piston and the compressed air acting on theother piston,

3. A device as specified in claim 2, characterized by the fact that thepiston operating in the compressed air cylinder has a largerarea thanthe piston operating in the charging cylinder.

4. A device as specified in claim 1, characterized by connections fromsaid Valve mechanism to the cylinders and reservoir and to theatmosphere, and means whereby the piston element actuates the valvemechanism in response to a predetermined reduction in the quantity ofliquid in the charging cylinder to disconnect the compressed air fromthe respective end of the piston and evacuate the compressed aircylinder.

5. A device as specified in claim 1, characterized by connections fromsaid valve mechanism to the cylinders and reservoir and to theatmosphere, and means whereby the piston element actuates the valvemechanism in response to a predetermined reduction in the quantity ofliquid in the charging cylinder to disconnect the compressed air fromthe respective end of the piston and evacuate the compressed aircylinder, and means whereby the valve mechanism connects the compressedair from the source to the reservoir after disconnecting the compressedair from the compressed air cylinder.

6. A device as specified in claim 1, characterized by a connection fromsaid valve mechanism to the ylinders and reservoir and to theatmosphere, and means whereby the piston element actuates the valvemechanism in response to a predetermined reduction in the quantity ofliquid in the charging cylinder to disconnect the compressed air fromthe respective end of the piston and evacuate the compressed aircylinder, means whereby the valve mechanism connects the compressed airfrom the source to the reservoir after disconnecting the compressed airfrom the compressed air cylinder, and means carried by the pistonelement for operating the valve mechanism.

7 A device as specified in claim 1, characterized by connections fromsaid valve mechanism to the cylinders and reservoir and to theatmosphere, and means whereby the piston element actuates the valvemechanism in response to a predetermined reduction in the quantity ofliquid in the chargin cylinder to disconnect the compressed air from therespective end of the piston and evacuate the compressed air cylinder,means whereby the valve mechanism connects the compressed air from thesource to the reservoir after disconnecting the compressed air from thecompressed air cylinder, means carried by the piston element foroperating the valve mechanism, the charging cylinder being provided withan outlet for the liquid, the piston element being adapted to move fromone limiting position to another as a predetermined amount of liquid issupplied to and withdrawn from the charging cylinder, and means wherebythe piston element actuates the valve mechanism when the piston elementreaches the limiting positions.

WILLIAM MESSINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 202,660 Maguire Apr. 23, 18781,380,603 Smythe June '7, 1921

